The invention is based on a blower motor as defined generically by the preamble to claim 1.
Blower motors for motor vehicle heating systems are as a rule accommodated in a housing pot, which is fastened by its fastening flange to an opening in the heating system and tightly closes off the opening. To prevent vibration and structure-borne sound from being transmitted to body parts and causing noise, damping elements are disposed between the blower motor and the fastening points. The damping elements for instance comprise rubber-elastic damping and sealing rings, which are disposed in the fastening region of the fastening flange and/or between the blower motor and the housing pot and seal off the heating conduit.
Individual damping elements can also be located on the bottom of the housing pot and secured to the housing pot, protruding with their face end into the interior of the housing pot and forming axial bearing points for the blower motor. First, the individual damping elements are mounted, and then the blower motor is inserted into the housing pot. Because of the strong frictional forces between the blower motor and the damping elements, blower motors can be mounted only with difficulty. The fastening flange formed onto the housing pot is furthermore adapted to each vehicle type and to a specific application, so that every geometric variant in fastening the heating system requires a complete new flange and housing pot part. The wide variety of parts also makes stockkeeping and logistics difficult.
Another bearing comprises premounting an adaptor on the blower motor, with the adaptor receiving damping elements distributed over the circumference. The damping elements secure the location of the blower motor both axially and radially. Although by means of the adaptor various blower motors can be assigned to one housing pot, nevertheless this is feasible only for the additional adaptor, which further increases the number of parts and makes assembly and production more complicated and expensive.
The blower motor can also be mounted on the heating system by means of a fastening frame. This frame has three struts distributed over its circumference, whose ends have fastening eyelets with rubber elastic parts. The combination of mechanical fastening and decoupling, however, limits the choice of optimal physical properties of the damping elements, because these elements must have not only good damping properties but also adequate strength. The resultant compromises in terms of internal friction, Shore hardness, relaxation and temperature resistance accordingly do not always lead to adequate decoupling. Since furthermore there is a general need to avoid the escape of leaking air in the region of the blower motor, when a blower motor is mounted in the above-described fastening frame, an additional cover on the back side of the blower motor is necessary as well.
According to the invention, at least one annular damping element is disposed between a housing pot and a fastening region of a fastening flange. This damping element can be designed exclusively in view of damping needs and can have an adequate volume, without structurally affecting the relationship of the blower motor to the housing pot or increasing the structural volume of the housing pot. Moreover, because of the annular design of the damping element, the sealing off of the mounting opening of the housing pot is preserved. For sealing off the fastening flange directly at the fastening region as well as for sealing off a gap between the blower motor and the housing pot, small-volume sealing means in the form of sealing rings or sealing coatings suffice. The blower motor is fastened in a simple way, mechanically directly, in the housing pot, as a result of which on the one hand fewer components are needed, while on the other hand, assembly is simplified.
In order to meet various demands made of the damping, it is expedient that the damping element comprises various parts whose materials have different physical properties. As a result, in particular, different damping properties in the radial direction and in the circumferential direction can be attained.
In one feature of the invention, it is provided that the housing pot has a travel limitation in the circumferential direction and/or in the radial and/or axial direction relative to the fastening region. Especially if there is a soft, subcritical adaptation of the damping elements, this prevents them from being overloaded in the event of load surges, such as when the blower motor is turned on or when shocks occur, and prevents the blower motor from executing excessively long motions and striking adjacent parts. The travel limitation can be embodied in a simple way by oblong slots on the fastening flange, which are engaged by extensions of the housing pot on the face that are embedded in damping elements. After a predetermined damping travel, the extensions are blocked by the contours of the oblong slots.
The fastening flange expediently comprises an inner and an outer part. The parts are joined to one another via the annular damping element. The inner part of the fastening flange can be formed onto the housing pot or secured either nondetachably or detachably, while the outer part has the fastening region on its outer edge. The connection between the outer part and the inner part can be designed in various ways and adapted to installation conditions. Expediently, the outer part overlaps the inner part, and the damping element is disposed in the region of the overlap. The damping element can be joined to the parts by vulcanizing, gluing, or an injection molding process, especially a two-component injection molding process. It is also possible to fix the damping element between the outer and inner parts by mechanical fastening means, such as rivets or screws, using shims; the fastening elements are decoupled from the parts of the fastening flange by further damping elements.
For the durability of the damping elements, it is most favorable if they are under thrust or pressure. Thus in one feature of the invention, in a horizontal installation of the blower motor, the fastening flange is embodied in such a way and the annular damping element is disposed in such a way that it is under pressure. For a targeted soft adaptation of the damping element, in individual applications, it may also be expedient, however, for the damping element to be under tension.
To obtain a one-piece fastening flange, it is expedient to dispose the damping element between the housing pot and the fastening flange. The damping element can be joined to one or both parts solidly or detachably. The detachable connection has the advantage that various fastening flanges can be combined with one housing pot, so that with only a few parts a wide variety of variants can be offered. One simple design is obtained if the damping element surrounds the housing pot and is gripped by a collar formed onto the fastening flange. The axial length of the collar brings about good bracing of the blower motor and can be adapted to the tilting moments and thrust forces exerted by the blower motor.
To secure the blower motor axially in the housing pot, it can be expedient to provide a cap, which is braced on the face end via a further damping element on the motor and/or the housing pot and is clipped to axial protrusions of the fastening flange. The axial protrusions expediently rest on a shoe-shaped receptacle for the annular damping element, which contacts the circumference of the housing pot.
In a further feature of the invention, a ventilation conduit is provided, which is connected to the outer part of the fastening flange and is decoupled from the housing pot by an additional annular damping element. Because of the good air circulation, the blower motor is adequately cooled and is protected against overheating.
To enable better mounting of the blower motor, it is advantageous to divide the housing pot along a longitudinal or transverse plane. If it is divided along a transverse plane, the flange in the annular damping element are disposed in the region of the parting plane, and the damping element can advantageously be glued to the housing pot or otherwise joined to it on the outer circumference on both sides of the parting seam. If the division is along a longitudinal plane, the damping element and the flange press the two parts together at the parting faces.
Further advantages will become apparent from the ensuing drawing description. In the drawing, exemplary embodiments of the invention are shown. The drawing, description and claims include numerous characteristics in combination. One skilled in the art will expediently consider the characteristics individually as well and put them together to make appropriate further combination.